000
AXPZ20 KNHC 270321
TWDEP 

TROPICAL WEATHER DISCUSSION
NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL
0405 UTC SAT FEB 27 2010

TROPICAL WEATHER DISCUSSION FOR THE EASTERN PACIFIC OCEAN FROM 
THE EQUATOR TO 32N...EAST OF 140W. 

BASED ON 0000 UTC SURFACE ANALYSIS AND SATELLITE IMAGERY THROUGH 
0300 UTC.

...ITCZ...

THE AXIS IS CENTERED ALONG 07N77W TO 06N116W TO 04N140W. 
SCATTERED MODERATE ISOLATED STRONG WITHIN 180 NM N AND 150 NM S 
OF AXIS BETWEEN 83W AND 90W. SCATTERED MODERATE ISOLATED STRONG 
WITHIN 60 NM N AND 90 NM S OF AXIS W OF 115W. 


...DISCUSSION...

A LARGE UPPER LEVEL CYCLONE IS CENTERED WELL N OF THE DISCUSSION 
AREA WITH AN UPPER LEVEL TROUGH EXTENDING INTO THE W PART OF THE 
AREA N OF 20N WITH RIDGING PREVAILING E OF THIS FEATURE. THE 
SUBTROPICAL JET EXTENDS ACROSS THE AREA FROM 08N140W TO 15N125W 
ACROSS SOUTHERN MEXICO INTO THE SOUTHERN GULF OF MEXICO. S OF 
THE SUBTROPICAL JET...AN INCREASE IN ITCZ CONVECTION W OF 116W 
AS MENTIONED ABOVE HAS STRENGTHENED THE UPPER LEVEL RIDGE AND 
INCREASED UPPER LEVEL DIVERGENCE ALONG 05N W OF 116W. IN 
TURN...THIS HAS HELPED RESTRENGTHEN THE SUBTROPICAL JET TO THE N 
OF THIS CONVECTION WITH CORE SPEEDS INCREASING FROM 70 KT 
YESTERDAY EVENING TO 110 KT THIS EVENING AS DEPICTED IN 
SATELLITE DERIVED WINDS. ITCZ CONVECTION BETWEEN 82W AND 90W HAS 
HELPED MAINTAIN UPPER LEVEL RIDGING ALONG 5N E OF 90W. A 
WEAKENING IN THE UPPER LEVEL RIDGE DUE TO A LACK OF CONVECTION 
IN THE ITCZ BETWEEN 90W AND 115W HAS ENABLED A SHORT WAVE TROUGH 
TO FILL BETWEEN THESE FEATURES.

AT THE SURFACE...A DISSIPATING COLD FRONT EXTENDS ACROSS THE NW 
PART OF THE AREA FROM 30N128W TO 25N134W. WINDS BEHIND THIS 
FRONT ARE GENERATING A LARGE NW SWELL WITH COMBINED SEAS TO 
ABOUT 23 FT. THIS FRONT WILL WEAKEN AND DISSIPATE OVER THE NEXT 
24 HOURS. E OF THE FRONT...DISSIPATING 1022 MB SURFACE HIGH PRES 
IS CENTERED NEAR 23N128W AS DEPICTED BY LATEST ASCAT AND WINDSAT 
PASSES. A SHRINKING AREA OF 20-25 KT NE-E TRADES PERSISTS IN THE 
TRADEWIND BELT W OF 120W. THE TRADES WILL WEAKEN AND DIMINISH IN 
COVERAGE OVER THE NEXT 48 HOURS AS THE HIGH PRESSURE DISSIPATES.

A TIGHT PRES GRADIENT ALSO EXISTS IN THE GULF OF CALIFORNIA WITH 
A TROUGH OVER INTERIOR MEXICO AND THE HIGH W OF BAJA CALIFORNIA. 
NW WINDS OF 20 KT CONTINUE FROM 26N TO 29N AS CONFIRMED BY THE 
LATEST ASCAT PASS. WINDS WILL DIMINISH TO LESS THAN 20 KT 
TONIGHT AS THE HIGH DISSIPATES. 

NW SWELLS CONTINUE TO GRADUALLY SUBSIDE ACROSS THE AREA...BUT 
ANOTHER NW SWELL GENERATED BEHIND THE COLD FRONT MENTIONED ABOVE 
WILL SPREAD ACROSS THE AREA THROUGH THE FORECAST PERIOD. 

GAP WINDS...
WINDS ARE LIGHT IN THE GULF OF TEHUANTEPEC AT THIS TIME ALTHOUGH 
THEY WILL QUICKLY INCREASE EARLY SAT AS A STRONG COLD FRONT 
PUSHES THROUGH THE BAY OF CAMPECHE AND GULF OF MEXICO. STRONG 
NORTHERLY WINDS WILL BE FUNNELED THROUGH THE CHIVELAS PASS AND 
INTO THE GULF OF TEHUANTEPEC INCREASING TO 20 TO 25 KT SAT 
MORNING AND THEN TO GALE FORCE LATE SAT AFTERNOON/EARLY EVENING. 
WINDS WILL DIMINISH TO LESS THAN GALE FORCE EARLY SUN AS THE 
FLOW IN THE BAY OF CAMPECHE N OF THE ISTHMUS OF TEHUANTEPEC 
VEERS.

WITH THE COLD FRONT DISSIPATING OVER THE SW CARIBBEAN...WINDS IN 
THE GULF OF PAPAGAYO HAVE DIMINISHED BELOW 20 KT. AS THE NEXT 
COLD FRONT THAT SHIFTS ACROSS THE GULF OF MEXICO TONIGHT AND 
EARLY SAT REACHES NICARAGUA IN THE SW CARIBBEAN...WINDS WILL 
INCREASE AGAIN TO 20 KT SUN.

FOR ADDITIONAL INFORMATION PLEASE VISIT 
HTTP://WWW.HURRICANES.GOV/MARINE

$$
AL